In the last post, I said that having a quiet machine was an objective of mine. Measuring acoustic levels is tricky if you want valid comparisons across manufacturers and models. Fortunately, there is an internationally standardized test procedure for computers and workstations, ISO 9296. Unfortunately, it’s difficult for prospective computer buyers to get the numbers. I’ve done a lot of legwork, and here’s what I’ve found.
Apple does not disclose the acoustic noise of Mac Pros. Several Apple sales engineers have given me the same answer, and they phrased it about that way, not, “I can’t find the numbers you’re looking for.”
Lenovo reports (declares is the ISO language) one number for the whole x20 line of machines. My guess is that it’s for the loudest machine. The declared sound pressure level is 35db at the operator’s position, both at idle and with an SATA disk operating. This is pretty loud by today’s desktop standards, although quiet compared to big servers. On their web site, Lenovo does talk about the noise from one of the smaller x20 machines being 24db, but they don’t specify how the measurements are taken.
Hewlett-Packard declares the Z600’s operator-position noise in floor-mount configuration to be 22db at idle and 23db with disk activity. That’s for a single processor configuration; for dual processors, the numbers are 32db and 33db, a bigger difference than I would have thought. For the Z800, a uniprocessor configuration is 21db and 22db, and a two-processor machine produces 28db and 31db. Hewlett-Packard uses disk mounting trays with acoustical isolation properties.
The Dell T7500 single-processor floor mounted workstation produces 28db SPL idling and active. The T7500 dual processor yields 31db for both.
A floor-mounted Dell T5500 single-processor produces 25db SPL idling and active. The T5500 dual processor yields 28db at idle, and, weirdly, a db less under use.
Of the workstations I’m considering, the Z800 is the quietest. In fact, the Z800 numbers are so good it’s hard to believe.
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